Bank 1 is where the number one cylinder/spark plug is located. If this is a 4 cylinder engine, number 1 is at the front of the motor and bank 1 is irrelevant and the number 1 sensor would be the one screwed into the exhaust manifold attatched to the cylinder head. If it is a 6 cylinder than number one is on the side closest to the radiator, and
Come along as we show you how to replace your spark plugs on the SECOND generation Ford 3.5L & 3.7L Duratec V6 engines. The Ford Flex did not get the update